Multiple string well packer



Jan. 24, 1967 Filed Sept. 50 1963 C. C. BROWN MULTIPLE STRING WELL PACKER 6 43: T mil 36 E KE 7 T \& 1 55---- i K 4 pll' 40" (A 3 Sheets-Sheet 1 ClC'/?0 0. BROWN INVENTOR.

Jan. 24,1967 (3. c. BROWN 3,299,959

MULTIPLE STRING WELL PACKER Filed Sept. 50, 1963 5 Sheets-Sheet 2 1967 c. c. BROWN 3,299,959

MULTIPLE STRING WELL PACKER Filed Sept. 30, 1965 3 Sheets-Sheet 3 C/CERO 6. BROWN A TTOE/VE 75 g, INVENTORI M M v United States Patent- Ofifice 3,299,959 Patented Jan. 24, 1967 3,299,959 MULTIPLE STRING WELL PACKER Cicero C. Brown, 8490 Katy Road, Houston, Tex. 77007 Filed Sept. 30, 1963, Ser. No. 312,724 9 Claims. (Cl. 166-120) This invention relates to new and useful improvements in well packer assemblies.

Well packer assemblies capable of holding differential pressures from either above or below require the use of two anchoring units, one for maintaining the assembly against upward displacement and the other for preventing downward displacement. The setting of the anchoring units presents no particular problem and several types are in general use wherein the anchoring units, as well as the packing element of the assembly are moved into set and sealing position hydraulically by the application of pressure fluid. However, where two anchoring units which look the assembly against movement in either direction are used, the release of the units to permit removal of the assembly presents a considerable problem.

Various attempts have been made to provide releasable means for this type of well packer assembly and one example is illustrated in my co-pending application Serial No. 69,118 filed November 14, 1960, now Patent No. 3,142,338 dated July 28, 1964. In such application, release of the assembly from its set position is effected by imparting a rotation to the tubing string on which the assembly is mounted. This is a satisfactory structure and accomplishes the purposes, provided that the packer assembly is not at too deep an elevation within the well. However, the deeper within the well bore that the assembly is located the more difficult it becomes to manipulate or rotate the tubing string in order to release the assembly. Furthermore, since release is dependent upon tubing rotation operating a threaded connection, rust and corrosion may jam the same to make release difficult; also, the well head equipment must be disturbed before such rotation can be imparted to said tubing and, under some circumstances, it may not be desirable to uncouple said well head equipment prior to unsetting of the well packer assembly.

It is, therefore, one object of this invention to provide a multi-string well packer assembly having means for locking same against movement in either direction within the well bore, together with hydraulically-actuated means, for releasing said locking means to permit removal of the complete assembly from the well bore.

Another object is to provide a multi-string well packer assembly having upper and lower gripping units for locking the assembly against movement in either direction within a well bore, wherein said gripping elements are moved into set or gripping position by a hydraulicallyactuated means and are retracted into released or nongripping position by additional hydraulically-actuated means, whereby release of said gripping units is effected without any movement or rotation of the tubing string on which the assembly is mounted and without disturbing the control head equipment at the well surface.

An important object of the invention is to provide a multi-string well packer assembly, of the character described, wherein the anchoring units are moved into a set or gripping position by the application of a suitable pressure and are constructed to remain in set position even though the pressure, which initially moved said elements to such set position, is relieved, the assembly also including normally inactive means which is adapted, by the application of pressure in one of the tubing strings upon which the packer is mounted, to apply pressure to said anchoring units in a direction effecting release thereof from a gripping position. I

A particular object is to provide a multi-string well packer assembly of the character described in which the packer can be both set and released hydraulically without moving the tubing strings which are suspended from the usual tubing head.

Still another object is to provide a multi-string well packer assembly in which the support is constructed of telescoping sections, one of which carries one of the anchoring units and its packing element and the other of which carries the second anchoring unit and its packing element, together with hydraulically-actuated means for controlling the movement of the sections relative to each other to thereby control the release of said assembly.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and where- FIGURE 1 is a sectional view of a rnulti-string well packer assembly, constructed in accordance with the invention, and illustrating the various par-ts in the position they assume during lowering of the assembly into the well bore;

FIGURE 2 is a similar view showing the packer in the fully set and anchored position in the well bore;

FIGURE 3 is a similar view illustrating the packer in a partially unset position with the sealing elements retracted; 7

FIGURE 4 is a similar view showing the packer in fully retracted position;

FIGURE 5 is a horizontal cross-sectional view taken along line 5-5 of FIGURE 3;

FIGURE 6 is a horizontal cross-sectional view taken along line 66 of FIGURE 1;

FIGURE 7 is a horizontal cross-sectional view taken on line 7-7 of FIGURE 1; and

FIGURE 8 is a schematic view showing the packer in a released position suspended from the well head by the tubing strings.

In the drawings, T-l designates the first tubing string and T-2 designates the second tubing string which extend downward through a well casing 10 within a well bore W. For purposes of clarity, the illustrations and description of the present invention are shown with a dual tubing string, but, as can hereinafter readily be determined, the device of the present invention has application to all multi-string tubing installations and should not be limited to the dual string tubing installation. The improved well tool assembly which is herein shown and described as a multi-string well packer assembly is gen erally indicated by the letter P (FIG. 8) and is connected at the desired point in the tubing strings. The tubing strings T-l and T-Z are suspended from the usual tubing head 11, which forms part of the surface control equipment E and the usual flow control valves 12 and 12a are disposed in the upper end of tubing strings T4 and T-2 respectively to control the flow therethrough.

The packer assembly P is adapted to be lowered into proper position within the well casing 10 by means of first tubing string T-l and during such lowering the packer is in an unset position. After reaching the desired depth within the casing, second tubing string T2 is run and engaged within packer assembly P through the use of the J-slot connection illustrated in FIGURES 2, 3 and 4. When second tubing string T2 is properly positioned, the control head equipment E is properly mounted to close in the upper end of said well casing 10 and at this time the well is under control. Thereafter, the packer assembly P may be moved into set or sealed position by the application of a hydraulic pressure through the bore of second tubing string T-2. After the packer assembly P is set, flow of well fluids from the producing formation below said assembly is upward through the tubing strings T-1 and T-2 with the production immediately below packer assembly P flowing upward through tubing string T-2 and the production from the next lower formation flowing upward through tubing string T1. When it is desired to remove the packer assembly P and the well tubing strings T-1 and T-2, the packer assembly is moved into a released position by the application of a fluid pressure through the bore of tubing T1. The packer assembly is one which can be set by hydraulic pressure and can be released by hydraulic pressure, whereby no movement or manipulation of the tubing strings T-1 or T-2 is required at any time. This provides a very decided advantage of permitting the surface control equipment E to remain in place at all times so that the well is completely under control during setting and releasing of the packer assembly.

The particular construction of the packer assembly is illustrated in FIGURES 1 through 7. Referring to FIGURE 1, which illustrates the packer assembly in an unset position for running in a well bore W, said assembly includes, head member B, releasing mechanism or means R, upper packing element 13, upper anchoring assembly or unit A, setting mechanism or means S, lower anchoring assembly or unit A1 and lower packing element 14.

Head member B is bored and internally threaded to receive tubing string T-l and is bored and provided with pin to receive tubing string T-2 which is provided with J-slot 16 for engagement with pin 15. The upper surface of head member B is suitably formed to assist in the landing of second tubing string T2 after the well packer assembly P has been run into well casing 10 to the desired depth. The lower portion of head member B is externally threaded and connected by such external threads to cylinder 17. Piston 18 extends upward in the bore within head member B connecting to first tubing string T-l in sliding engagement and is in sliding engagement with the inner surface of cylinder 17. The lower end of piston 18 is internally threaded to receive the upper outward enlarged section 19 of mandrel 20. Mandrel 20 extends downward through well packer assembly P and is externally threaded at its lower end for engagement with collar 21. Collar 21 provides external abut ment 21a at the lower end of mandrel 20. Collar 21 is externally threaded to provide" connection for the portion of first tubing string T-l extending below well packer assembly P as best shown in FIGURE 8. Mandrel 22 is threaded into the lower portion of head member B into connection with the bore into which second tubing string T2 connects and mandrel 22 has external shoulder 22a as shown. The lower portion of cylinder 17 surrounds mandrels 20 and 22 and the areas of contact are suitably sealed as shown. Piston 18 surrounds mandrel 22 in sliding engagement therewith and is suitably sealed to prevent leakage of pressure fluids therebetween. Upper enlarged section 19 of mandrel 20 is provided with ports 23 and valve sleeve 24 having ports 25 is releasably secured within section 19 by shear pin 26. The lower portion of cylinder 17 surrounding mandrel 20 is provided with recess 17a having shoulder 17b for receiving and engaging the lower portion of section 19 of mandrel 20, as hereinafter more fully explained in relation to the operation of releasing mechanism R. The lower outer annular portion of cylinder 17 is flared downward and inward and engages backing element 27 which is in engagement with upper packing element 13. As shown in FIG- URE 1, backing element 27, upper packing element 13 and backing element 28 engaging the lower portion of upper packing element 13 completely surround mandrel 20 and mandrel 22 and are in unset position out of engagement with the inner surface of well casing l0.

Upper anchoring assembly A includes cones 29 and slips 30. As shown, cones 29 surround mandrel 20 and mandrel 22 and their upper surface engages the lower surface of backing element 28. Slips 30 are engaged in the upper portion of piston 31 by means of T-shaped connections 32 as best shown in FIGURE 8,

Setting mechanisms include piston 31 and cylinder 33 which, as shown in FIGURE 1, are releasably connected by shear pin 34. Piston 31 surrounds mandrels 20 and 22 and is provided with suitable sealing means for sliding engagement therewith. Cylinder 33 surrounds the lower portion of piston 31 and extends downward beyond the lower edge of piston 31 into a sliding engagement with mandrels 20 and 22 which engagement is suitably sealed. Piston 31 is provided with a vertically extending slot 35 and pin 36 extends through the upper portion of cylinder 33 in threaded engagement therewith and into sliding engagement with vertical slot 35 in piston 31. In the unset position as shown in FIGURE 1, pin 36 is positioned at the top of vertical slot 35. The lower portion of piston 31 surrounding mandrel 22 is recessed as shown at 37 to receiver shoulder 38 on mandrel 22. Ports 39 extend through mandrel 22 and in the unset position of the well packer assembly P, as shown in FIGURE 1, connect into the recess 37. The lower portion of cylinder 33 surrounding mandrel 20 is provided with recess 40 to receive snap ring 41 which is positioned and extends outward from a groove around mandrel 20.

The lower portion of cylinder 33 is provided with T- shaped connection 42, as shown in FIGURE 8, to receive slips 43. Lower anchoring assembly A-l includes slips 43 and cones 44. The interior of cones 44 surrounding mandrel 20 is provided with a recess 45 which receives snap ring 46 and engages the lower edge of snap ring 46 when in the unset position. Snap ring 46 is positioned in and extends from a groove around mandrel 20. The lower surface of cones 44 are in engagement with backing element 47 which is positioned on the upper surface of lower packing element 14. Backing element 48 is positioned between lower packing element 14 and header 49 and header 49 is engaged from below by external abutment 21a of collar 21.

Valve sleeve 50 is releasably secured in the lower portion of mandrel 22 by shear pin 51.

Referring to releasing mechanism R, ports 52 extend through the lower portion of the part of piston 18 which extend into head member B. Ports 52 connect into the chamber 53 formed between the lower surface of head member B and the upper surface of piston 18. Chamber 54, as best seen in FIGURE 5, surrounding mandrel 20 and mandrel 22 and within cylinder 17, is substantially filled with a liquid to prevent the accidental release of well packer assembly P. Valve sleeve 24 therefore provides a means for locking the piston 18 in position in cylinder 17 by sealing the liquid therein.

With well packer assembly P positioned at the depth desired, the interrelation of the component parts will be as shown in FIGURE 1. At this time, second tubing string T-2 is run into the well and secured with J-slot 16 connection to pin 15 in head member B, as shown in FIG- URE 2. With second tubing string T-2 positioned, setting mechanism is initially actuated by dropping setting plug or ball 55 down through second tubing string T-2. It should be noted that the outer diameter of setting plug 55 is smaller than the inner diameter of second tubing string T-2 and the inner diameter of mandrel 22, but larger than the inner diameter of setting sleeve 50. Any suitable plug or ball device may be used which will provide a liquid seal in cooperation with valve sleeve 50 in the lower end of mandrel 22. As shown in FIGURE 2, a ball is used for this service.

Wit-h setting plug 55 in position on setting sleeve 50 sealing the lower end of mandrel 22, liquid, such as a well fluid is pumped down tubing string T2 under sufiicient pressure to force the liquid through. ports 39 in mandrel 22 and cause piston 31 to be forced upward and cylinder 33 to be forced downward. The upward movement of piston 31 will force slips 3t) upward on cones 29. The angle of cones 29 will cause the upward movement of slips 30 to move slips 30 outward into engagement with the inner surface of well casing 10. Slips 30 are preferably the type which will, once engaged, move upward but not downward. Further upward movement of piston 31 will compress upper packing element 13 into engagement with the inner surface of well casing 10, packing the upper portion of well packing assembly. The downward movement of cylinder 33 will move slips 43 downward on cones 44, whose angle will cause slips 43 to engage the inner surface of well casing 10. Slips 43 are preferably the type which will move downward of the slips while in engagement with casing 10, but will not move upward. Therefore, further downward movement of cylinder 33 will be transmitted to lower packing element 14-, causing a compression of lower packing element 14 into engagement with the interior of well casing 10, providing a lower packing of well packer assembly P.

It can be seen that with slips 43 limiting any movement in an upward direction, and slips 30 limiting any movement in a downward direction, that, as shown in FIG- URE 2, the well packer assembly P is completely anchored within well casing and provided with packing bot-h above upper anchoring assembly A and below lower anchoring assembly A4. The pressure initially applied to the interior of mandrel 22 for setting must be SllfilClEHt to shear pin 34 before piston 31 and cylinder 33 will move. Compression of upper packing element 13 is attained by the upward movement of piston 31, since this movement is upward with respect to mandrel 22 and head member B, and since cylinder 17 is secured to head member B providing resistance to upward movement, causing the desired compression of upper packing element 13 to provide a suitable upper packing. Header 49 also resists the downward movement of cones 44 and therefore provides adequate compression of lower packing element 14-, thereby providing adequate lower packing for the device.

When well packer assembly P is completely set, as shown in FIGURE 2, additional pressure is applied to second tubing string T2 and into mandrel 22. This pressure is sufficient to cause shear pin 51 to shear and allow valve sleeve 50 and setting plug 55 to be discharged through the bottom of mandrel 22 whereby tubing string T2 will be free of obstruction and ready for the flow of production fluids therein. Discharge of valve sleeve 50 and setting plug 55 from mandrel 22 will allow a release of pressure between piston 31 and cylinder 33, but the slips 30 will prevent piston 31 from moving in a downward direction and slips 43 will prevent cylinder 33 from moving in an upward direction. Therefore, maintaining the set of well packer assembly P is not dependent upon the maintenance of pressure within mandrel 22. In the position of piston 31 and cylinder33, as shown in FIGURE 2,

it should be noted that pin 36 has traveled downward in slot 35 approximately one-half the length of slot 35.

With well packer assembly P positioned as shown at FIGURE 2, and with suitable tubing Tl extending from collar 21, and suitably packed below the producing formation whose upper level is defined by well packing assembly P, production of well fluids may flow upward through first string tubing Tl and second string tubing T2.

Release of well packing assembly P is accomplished by dropping setting plug or ball 56 into first tubing string T1. The outer diameter of setting plug 56 is smaller than the inner diameter of first well string tubing T1 and the upper extension of piston 18 into head member B, but larger than the inner diameter of valve sleeve 24. Plug 56, when dropped through first string tubing T1, will alight and seat on the upper edge of valve sleeve 24. A liquid, preferably well fluids, is then pumped into first tubing string T1 and sufficient pressure is built up to shear until it is desired to release this member.

6 pin 23, allowing valve sleeve 24 to drop within enlarged section 19 of mandrel 22 and causing ports 25 to come into registry with ports 23 in enlarged section 19 of mandrel 20. The alignment of ports 25 and ports 23 will allow the liquid in chamber 54 to be discharged therethrough and to flow downward through mandrel 20. At the same time, liquid under pressure in first tubing string T-l will be retained above plug 56. The liquid above plug 56 will flow through ports 52 into chamber 53 above piston 18 and below head member B, causing piston 18 and mandrel 20 to move downward in relation to head member B and mandrel 22. This movement will lower ports 23 in chamber 54, allowing any liquid in chamber 54 to be pumped out into mandrel 20 below plug 56. This downward movement of mandrel 20 will relieve the compression on lower packing element 14, since collar 21 and header 49 will also move downward. Further, the downward movement of piston 18 and mandrel 20 will cause snap ring 46 to engage with the recess 45 of cones 44, withdrawing cones 44 from under slips 43, thereby causing slips 43 to move out of engagement with the inner surface of well casing 10. Further movement of mandrel 20 will cause snap ring 41 to engage recess 40 of cylinder 33, moving cylinder 33 in a downward direction until pin 3.6 engages the bottom of vertical slot 35 in piston 31. At this point further downward movement of piston 31 will be prevented by the engagement of slips 30 within the wall of casing 10. Therefore, head member B will be pumped upwardly and allow upper packing element to relax. Further upward movement of head member B in response to pressure will raise mandrel 22 and cause engagement between shoulder 22a on mandrel 22 with the lower edge of cones 29 whereby cones 29 will be removed from under slips 30. This upward movement of cones 29 will cause the release of slips 30 from the interior of well casing 10. At this point well packer assembly P has been completely released, as shown in FIGURE 4 and may be withdrawn with the tubing string T1 or T2 from well casing 10.

From the foregoing it will be evident that a multi-string well packer assembly is provided which may be efficiently set into sealing and anchoring position by the application of pressure through one of the well tubing strings. Also, when it is desired to release the anchoring units and to return the packing elements to the normal non-sealing position, this may also be accomplished by applying pressure to another of the tubing strings. No manipulation, either longitudinal or rotational, of any of the tubing strings is necessary, so that the setting and releasing of the multi-string well packer assembly may be carried out without disturbing any of the tubing strings and without dis-' turbing the surface control equipment E at the surface of the well. The use of a release cylinder and piston makes it possible to trap an incompressible liquid within the release cylinder to lock the release piston against movement This provides a simple and eflicient means for quickly and easily releasing the anchoring units and moving the packing elements to their normal non-sealing position.

Since the assembly includes both upper and lower pipe or well bore anchoring units, it comprises a permanent pipe packer which is held against movement in either direction. Any pressure from below the packer assembly when the same is in its set position will merely act against the lower packing element 14 and will be applied to cones 44 to urge the lower anchoring slips 43 into tighter anchoring engagement. Similarly, if pressure above the packer is greater, this pressure acts downward upon upper packing element 13 and its force is transmitted to cones 29 to urge slips 30 into tighter anchoring engagement. Although employing two anchoring units which lock the assembly against either upward or downward movement, it is possible through the release cylinder and piston arrangement to readily accomplish retraction of the packing elements and anchoring units. As above noted, the

results are accomplished by applying hydraulic pressure through first tubing string T-1 whereby movement or rotation of the tubing which would disturb the surface control equipment is not required to release the multi-string well packer assembly.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

1. A multi-string well packer assembly for connection in well tubing strings within a well bore including,

a head member connected 11 said tubing strings,

a first mandrel connected to said head member for limited longitudinal movement relative thereto,

a second mandrel secured to said head member in side-by-side parallel relationship to said first mandrel,

an external abutment on the lower end of said first mandrel,

means locking said first mandrel against movement relative to said head member to lock said external abutment in spaced relationship to said head member,

an upper anchoring unit for anchoring the assembly in the well bore and an upper packing element for sealing with the well bore mounted on said mandrels adjacent said head member,

a lower anchoring unit for anchoring the assembly in the well bore and a lower packing element for sealing with the well bore mounted on the said mandrels adjacent said external abutment,

a first hydraulically-actuated means carried by said second mandrel and located between said upper an choring unit and packing element and said lower anchoring unit and packing element for applying endwise force to the anchoring units and packing elements which are confined by said external abutment and said head member, whereby upon operation of said first hydraulically-actuated means said elements are deformed into sealing position and said anchoring units are anchored, and

a second hydraulically-actuated means forming part of said head member and coacting with said locking means and said mandrels for releasing said locking means and for moving said first mandrel relative to said head member in a direction which moves said external abutment away from said head member, whereby the force maintaining the packing elements in sealing position and the anchoring units in anchored position is relieved.

2. A multi-string well packer assembly as set forth in claim 1 wherein the means for locking said first mandrel against movement relative to said head member comprises a cylinder on said head member and a piston on said first mandrel,

together with means for trapping a liquid between one end of said cylinder and said piston to prevent movement of the piston and said first mandrel with respect to said cylinder and said head member.

3. A multi-string well packer .assembly as set forth in claim 1 wherein the means for locking said first mandrel against movement relative to said head member comprises a cylinder on said head member and a piston on said first mandrel,

together with means for trapping a liquid between one end of said cylinder and said piston to prevent movement of the piston and said first mandrel with respect to said cylinder and said head member,

said second hydraulically-actuated means including a valve which normally closes an escape port in said first mandrel,

movement of said valve to open position permitting escape of the trapped liquid from said cylinder to allow movement of said piston within said cylinder with resulting movement between said first mandrel and said head member.

4. A multi-string well packer assembly as set forth in claim 1, with means communicating one of the tubing strings with the first hydraulically-actuated means, whereby pressure fluid for actuating said first hydraulicallyactuated means may be conducted thereto through said tubing string. 7 5. A multi-string well packer assembly as set forth in claim 1, with means communicating one of the tubing strings with the first hydraulically-actuated means, whereby pressure fluid for actuating said first hydraulically-actuated means may be conducted thereto through said tubing string, and

means communicating another of said tubing strings with said second hydraulically-actuated means, whereby pressure fiuid for actuating said second hydraulically-actuated means may be conducted thereto through said latter tubing string.

7 6. A multi-string well packer assembly for connection in a well tubing string including,

a head member,

a first mandrel,

a second mandrel in side-by-side parallel relationship to said first mandrel,

said head member connecting said mandrels for limited longitudinal movement relative to each other,

means normally locking the mandrels against relative movement,

a lower packing element for sealing with the wall of the well and a lower anchoring unit for anchoring the assembly within the well mounted on said mandrels,

an abutment on the lower end of said first mandrel engageable with said lower packing element limiting the movement of said element in one direction,

an upper packing element for sealing with the wall of the well and an upper anchoring unit for anchoring the assembly within the well mounted on said mandrels,

said head member being engageable with said upper packing element for limiting the movement of said element in one direction,

hydraulically-actuated setting means carried by said mandrels and disposed between the upper packing element and upper anchoring unit and the lower packing element and lower anchoring unit,

co-acting means on said hydraulically-actuated means and said packing elements and anchoring units operable to move said packing elements toward said abutment and said head member engaging said elements to thereby set said packing elements and anchoring units when said means is actuated, and

hydraulically-actuated releasing means co-acting with the locking means and the mandrels for releasing said locking means to effect relative movement of said first mandrel with respect to said second mandrel in a direction to release and unset said packing elements and anchoring units.

7. A multi-string well packer assembly as set forth in claim 6 wherein,

the means for normally locking the mandrels against relative movement with respect to each other and the hydraulically actuated release means comprise a cylinder connected to said second mandrel and a piston connected to said first mandrel,

together with means for trapping fluid between one end of the cylinder and the piston to prevent movement of the piston within the cylinder to lock the mandrels against movement of said first mandrel relative to said second mandrel.

8-. A r'nulti-string well packer assembly as set forth in claim 6 wherein the means for normally locking the mandrels against relative movement with respect to each other and said hydraulically actuated release means comprise a cylinder secured to said second mandrel and a piston mounted on said first mandrel,

together with a valve which normally closes an escape port in said first mandrel for trapping fluid between one end of the cylinder and the piston to prevent movement of the piston within the cylinder to lock the mandrels against movement relative to each other, whereby movement of the valve to open position permits escape of the trapped fluid to allow movement of the piston within the cylinder and consequent movement of said first mandrel relative to said second mandrel.

9. A multi-string Well packer assembly for connection in a well tubing string within a well bore including,

a head member,

a first mandrel,

a second mandrel secured to said head member in side-by-side parallel relationship to said first mandrel,

a piston secured to said first mandrel,

a cylinder secured to said head member,

said piston and said cylinder being connected for limited longitudinal movement relative to each other,

an external abutment on the lower end of said first mandrel,

means locking said piston and said cylinder in a predetermined position relative to each other with said external abutment spaced from said cylinder,

an upper packing element and anchoring unit for supporting the assembly against downward movement in the well bore mounted on said mandrels and located adjacent said cylinder,

a lower packing element and anchoring unit for supporting the assembly against upward movement in the well bore and located adjacent said external abutment,

hydraulically-actuated means on said first and second mandrels between said upper packing element and anchoring unit and said lower packing element and anchoring unit for moving the elements and units into set position confined by said cylinder and said external abutment, and

means co-acting with said locking means and said piston and cylinder for releasing the locking means to permit movement of said piston and said first mandrel relative to said cylinder and said head member to thereby move said external abutment away from said lower packing element and anchoring unit whereby said packing elements and anchoring units are moved to an unset position.

References Cited by the Examiner UNITED STATES PATENTS 3,122,205 2/1964 Brown et a1. 166-12O X 3,191,682 6/1965 Cochran 166-120 3,224,508 12/1965 Cochran 166-120 JACOB L. NACKENOFF, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

9. A MULTI-STRING WELL PACKER ASSEMBLY FOR CONNECTION IN A WELL TUBING STRING WITHIN A WELL BORE INCLUDING, A HEAD MEMBER, A FIRST MANDREL, A SECOND MANDREL SECURED TO SAID HEAD MEMBER IN SIDE-BY-SIDE PARALLEL RELATIONSHIP TO SAID FIRST MANDREL, A PISTON SECURED TO SAID FIRST MANDREL, A CYLINDER SECURED TO SAID HEAD MEMBER, SAID PISTON AND SAID CYLINDER BEING CONNECTED FOR LIMITED LONGITUDINAL MOVEMENT RELATIVE TO EACH OTHER, AN EXTERNAL ABUTMENT ON THE LOWER END OF SAID FIRST MANDREL, MEANS LOCKING SAID PISTON AND SAID CYLINDER IN A PREDETERMINED POSITION RELATIVE TO EACH OTHER WITH SAID EXTERNAL ABUTMENT SPACED FROM SAID CYLINDER, AN UPPER PACKING ELEMENT AND ANCHORING UNIT FOR SUPPORTING THE ASSEMBLY AGAINST DOWNWARD MOVEMENT IN THE WELL BORE MOUNTED ON SAID MANDRELS AND LOCATED ADJACENT SAID CYLINDER, A LOWER PACKING ELEMENT AND ANCHORING UNIT FOR SUPPORTING THE ASSEMBLY AGAINST UPWARD MOVEMENT IN THE WELL BORE AND LOCATED ADJACENT SAID EXTERNAL ABUTMENT, HYDRAULICALLY-ACTUATED MEANS ON SAID FIRST AND SECOND MANDRELS BETWEEN SAID UPPER PACKING ELEMENT AND ANCHORING UNIT AND SAID LOWER PACKING ELEMENT AND ANCHORING UNIT FOR MOVING THE ELEMENTS AND UNITS INTO SET POSITION CONFINED BY SAID CYLINDER AND SAID EXTERNAL ABUTMENT, AND MEANS CO-ACTING WITH SAID LOCKING MEANS AND SAID PISTON AND CYLINDER FOR RELEASING THE LOCKING MEANS TO PERMIT MOVEMENT OF SAID PISTON AND SAID FIRST MANDREL RELATIVE TO SAID CYLINDER AND SAID HEAD MEMBER TO THEREBY MOVE SAID EXTERNAL ABUTMENT AWAY FROM SAID LOWER PACKING ELEMENT AND ANCHORING UNIT WHEREBY SAID PACKING ELEMENTS AND ANCHORING UNITS ARE MOVED TO AN UNSET POSITION. 